青藏铁路多年冻土区涵洞病害机理分析

Analysis of Culvert Defects Mechanism in Permafrost Region of Qinghai-Tibet Railway

为了防治青藏铁路多年冻土区涵洞病害,通过对4座涵洞的现场变形以及温度场监测,利用现场调查与监测数据分析,查明涵洞病害形成的7种不同原因。结果表明:青藏铁路的施工以及水热侵蚀引起地基多年冻土升温融化下沉以及冻土蠕变下沉是造成青藏铁路多年冻土区涵洞病害的主要原因。可通过减少和杜绝涵洞地基周围的水热侵蚀以及采取埋设热棒等工程措施进而达到防治涵洞病害的目的。

In order to control the culvert defects in permafrost region of Qinghai-Tibet railway, seven causes of the culvert defects are identified based on the monitoring of deformation and temperature field of four culverts, and field investigation and monitoring data analysis. The results show that the construction of Qinghai-Tibet railway and water erosion having resulted in ground temperature rising and permafrost thaw settlement subsidence and the creep of frozen soil are the root causes for the culvert defects in permafrost regions of Qinghai-Tibet railway. Reducing and preventing water and thermal erosion around culvert foundation and the use of buried hot rod are the effective measures to control the culvert defects.